Jonathan Ross, Kristin Scott-Thomas and Jade Jagger all proudly own one. Even the Lloyds TSB chairman Victor Blank was snapped stepping out of one on his way to a meeting to discuss the takeover of HBOS. They may look like Noddy cars, but for the green-conscious urban motorist, the G-Wiz was the guilt-free answer to getting around town.

But all that star power hasn't insulated them from a drastic slump in sales: according to figures collated by the Society of Motor Manufacturers and Traders, a total of just 156 electric cars were sold in the UK from January to October 2008, compared with 374 for the same period last year. The vast majority of the sales (and the 58% slump) are G-Wiz cars, made by Indian car company Reva.

Experts think the fall comes from a combination of factors, including the recent financial gloom, concerns about the safety of Reva's vehicle and the distant promise of electric cars from mainstream manufacturers.

"The whole motor industry has seen a slump in sales like they've never seen before in the last 20 years," said Steve Hartridge, managing director of Goingreen, which distributes the G-Wiz in the UK. "That has to be borne in mind so I'm not going to make any grand plans for next year."

Richard Bremner, editor of cleangreencars.co.uk, who unearthed the electric car sales figures, said: "People have maybe woken up to the fact that the electric vehicles that have been offered to date, they're not hugely appealing other than for their green credentials and they're only suitable for short journeys around town."

He added that the rising profile of proposed all-electric cars from Smart, Nissan and, more recently, an electric version of BMW's Mini, meant that potential customers may be delaying their purchases.

There are more than 1,100 all-electric cars already on UK roads, with the majority in London. The sales slump comes as the only other player in London's electric car market, the Nice Car Company, went into administration.

Set up two years ago, the company had been selling an all-electric version of the French-made Aixam Mega. Nice had planned to bring out more models, including a two-seater and an MPV by the end of the year but, according to Bremner, sales had dropped lately to less than a single car per week.

Bremner added that consumers could also have been put off the G-Wiz after it failed a crash test last year. Because the vehicle is considered a quadricycle rather than a car, it does not need to pass the stringent crash tests of the other cars on the road.

"Last year, they had some unfortunate publicity around the crash performance of that vehicle because Top Gear crash-tested one in the same way that you would a conventional car and it was found wanting," said Bremner.

Hartridge said the furore had no doubt had an impact on sales. "But we're through that period now. All the cars we sell now are crash-tested at 25mph."

Vicky Wyatt, Greenpeace transport campaigner said the sales car sales slump was worrying. "Electric cars have a key role to play in tackling climate change as well as reducing our dependence on foreign oil supplies.

"Sales should be going through the roof, and the fact that they are declining points to a failure on the part of government and manufacturers to make them more attractive to motorists in the UK."

She said the government should introduce lower road tax and excise duty, free parking, closed-loop battery recycling and urban plug in points.